Electromagnetic-wave-receiving system.



. E. B. D ALLIN. ELECTROMAGNETIC WAVE RECEIVING SYSTEM.

' APPLICATION FILED AUGJ4. I915- 1,202,168. Patented Oat. 24,1916.

EDWIN BERTRAM DALLIN, F ARLINGTON, MASSACHUSETTS.

ELEc'I'BontAGnE'TIo-WAVE-REOEIVING SYSTEM. 1

Specification oi Letters Patent.- fatentgd 1 241 1916.

Application filed August 14, 1915, Serial No. 45,549.

To all whom it may concern:

Be it known that-LEDWINB. DALLIN, a citizen of the UnitedStates, and a resident of Arlington, in the county of Middlesex and State of Massachusetts, have'invented a new and useful Improvement-in Electromagnetic-Wave-Receiving Systems, of which the following is "a specification;

My invention relates to electromagnetic wave receiving-systems and its object is to simplify the construction and improve the efliciency of the same in the manner hereinafter set forth. i

An illustrative embodiment'ofmy inven, tion is shown diagrammatically in the drawing which accompanies and forms a part of this specification; but it is to be understood that various modifications may be made both inthe particular apparatus and in the'cir-- cuit arrangements therein disclosed without t1on.

In the drawing, V represents a receiving.

departing from the principle ofniy invenconductor of any suitable construction,

herein shown as an elevated conductor, connected to ea'rthE throughthe inductance L and condenser 0 both of which preferably are adjustable; The circuit which includes the inductance L and condenser C both of which assho'wn preferably are adjustable, is

a tuned receiving' circuit, operatively connected with which in any suitable manner is a detector D and signal-indicating device-T. In the present instance, D rcpresentsa'crystal detector and T a telephone, anda condenser C' may be shunted across the terminals of said telephone, The inductances L and L are arranged at right angles to each other so that their mutual inductance is sub. stantially Zero'andithre is no electrical reaction between the receiving conductor and.

the. tuned receiving circui For the purpose of conveying the energy from the receiving conductor to the tuned receiving circuit, I employ an open circuit which includes the coil:- L L, each consist mg of'one or more turns, three turns being shown in the diagram, and said coils arepreferab1y .'c1osely coupled with theends of the inductances L L which are remote I from the adjustable contacts coo crating with the same, The said open circuit should have, very low 'resistance and practically} no capacity, and preferably; it is constructed of stranded wire.

In an electromagnetic-wave receiving. system, a receiving conductor including anarranlgled at right angles to each o Inasmuch as the reduction of mutual in-' 3 ductance between the inductancesL L is effected by the position of the same at right angles as distinguished from spatial separation, it is possible to locate the several coils and condensers, as well as the associated apparatus, in a relatively small and portable casing, and such casing may be provided with the usual instrumentalities for varying the inductance and capacity of the several coils and condensers in, the usual manner which is well understood and requires no description herein. It will be noted that the 'translation of energy from the receiving conductor to the tuned receiving circuit is effected electrostatically. l i

' I have found that for the same degree of selectivity or sharpness of tuning, the signals received-by my system are of greater intensity, other things being equal, than those received by an equivalent loosely-in 'ductivelycoupled system, and conversely with a given signal intensity, the selectivity of my system is superior to that of such equivalent loose-coupledsystem. I have also found that w th a given signal intensity the selectivity of my system is much higher than that obtained, other things being equal, when a closed circuit having very low resistance" and substantiallyno capacity, is in ductively related with the inductances L, L

both when the latter are arranged as above setforth orare so remote from each other that their mutual inductance is 'substantially zero. Having thus described one illustrativeem- ,bodi'ment of my invention, without however -lnnitmgthe same thereto, what I claim as new and desire ,to secure by'Letter-s Patent inductance, a tuned receiving circuit includ- .ing an inductance, said inductancesbeing arranged at right angles to each other, so that their mutual inductance is substantiallyzero, and anopen circuit inductively associated with said lncluctances.

2. In an electromagnetic-wave receiving,

system, a receiving conductor including an inductance a tuned receiving circuit including-an in uctance, said inductanccs being her, so eir mutual: inductance is substantially that 1:

- zero, and means for electrostatic-1111a trans system, a receiving conductor, a

laiing energy from said receiving conductor tq said receiving circuit;

3. in an elcctromugnetic'wme rcueiving tuned receiving circuit, and an mpen circuit inductively connected with said receiving conductor and said. receiving circuit.

In testimony whereof, I have hereunto subscribed my name this 13th day of August, 1915;

EDWIN BERTRAM DALLIN.

Witnesses: v

Gm). K. W'oonwoxrrn, B. TQMLINSQN. 

